Talked
to the OrCad guy here. He asked if it was an artifiact of GCPreview. He also
said it would be fairly easy to change the component library and correct the
drawing. He also noticed that the BGAs looked funny. Are they pads all the same
size on a component by component basis?
Do you
have the OrCad files? We would look at them for you but I bet you have a
non-disclosure issue.
What
about the solder stencile? What about the solder mask, do the big pads end up
SMD? That would be bad for sure.
-----Original Message-----
From:
TechNet [mailto:[log in to unmask]]On Behalf Of Steve
Gregory
Sent: Friday, June 21, 2002 2:54 PM
To:
[log in to unmask]
Subject: [TN] PCB lay-out
problem...
Hi all,
We're having a board lay-out
done outside, and as with new designs, I will get asked to look at the
preliminary gerbers to see if I can see anything out of place that might need
changing.
I looked the the gerbers that were given to me and the first
think I noticed was that on some IC footprints, there was 1 rectangular pad,
then 9 pads where the corners were rounded, then a rectangular pad, and on and
on...
So I fed that back to our engineer here who is over this
project, then he fed that back to the individual who is doing the lay-out. Our
engineer here then came back to me and asked if that would be a problem, and I
told him it could be, but why not make all the pads uniform? Go to:
http://www.stevezeva.homestead.com and look at "OrCad" to see what I mean.
His reply was that the individual doing the layout told him he would
have to go in and manually edit each one of the pads that were rectangular,
and that it would be too much trouble. He said this is the way OrCad put the
footprint down, and if it was such a problem, why would OrCad have this
footprint in the library? Then he added that the IPC-SM-782 says that you can
either use rectangular pads or optionally round the corners, so that tells him
you can use either one or both, and it doesn't make any difference. So he told
the layout person to leave things as they are.
I don't know anything
at all about OrCad, but something tells me there's an operator problem here.
I've never seen a footprint like this before, and no matter what I say, I
can't convince our engineer here that the footprint needs to be fixed.
HELP!!! PLEASE!!!
Thanks,
-Steve Gregory-